Driving Impressions: Prius Plug-In Hybrid

The Toyota Prius Plug-In Hybrid I was lucky enough to test drive for a week (complete with flashy side decals so everyone knew what I was driving) was one of the fleet of demonstrator cars making the rounds of press, academic, and industry types here in the U.S. The program gives Toyota feedback on the technology as well as user experience and expectations.

The car had a prototype Li-ion battery with 5.2 kWh capacity. Toyota says a production version of the battery will likely be reconfigured to better fit the available space (the rear deck lid is fairly high on the demonstrator) by the time production cars are sold starting in early 2012 (Sales will start in the 13 states that have adopted the California Zero Emissions Vehicle mandate).

The "electric range" reserve of the battery was depleted when the car arrived (with a full tank of gas). It took only three hours to recharge the battery (using the 110V charger that came with the car), which then allowed the car to go 13 to 14 miles in an EV only mode. But the plug-in Prius is no slouch on only electric power and runs at up to 60+ mph without using the gas engine. If you stomp the throttle while in the EV mode, the internal combustion engine will come on for additional power.

Sizing the battery for the 13 mi EV range was a compromise between "size, weight, and cost of the lithium-ion battery pack, all of which we wanted to keep within reasonable limits," said Toyota spokesman Wade Hoyt. If one's driving is less than or not much more than 13 miles until you're back home or near an outlet for a short charge, this editor can see the plug-in becoming an "in-town" electric vehicle.

Charging was aided by a "time to full charge" readout in the driver's center display. There was also a light on the dash visible from outside the car that goes out when the battery is fully charged. While on the charger, the driver is able to turn on the air conditioning, via the key fob, to precool the car in the summer using utility power. But there is no similar heating function for colder weather. I was also wondering why no remote window-roll-down feature is offered to help with summer cooling without use of the air conditioning.

On the road
Push the "start" button in the plug-in Prius and a "ready" light comes on to let you know all systems are go—the gas engine did not come on (as is often the case in a standard Prius to get it warmed up). I don't know if this was because my drive was in the summer weather or not. A self-centering shift "lever" (it's more like a sliding knob) puts the automatic transmission in the reverse, forward, or engine braking modes. The latter uses more aggresive engine braking to slow the car—but if you forget to return to the drive position, the cruise control won't activate.

But the big question with any alternative powertrain car is what was the fuel economy. First off, I noticed just a slight dip (only 0.1 miles) in the remaining EV range number when I switch on the climate control. After 310.4 miles, I filled up with 5.168 gallons of gas, for a mileage of 60.1 mpg (the onboard computer pegged mileage at 59.8 mpg). If you eliminate the electric range only mileage (I charged and depelete the battery through four complete EV cycles for about 53 miles), mileage was still a very respectable 49.8 mpg.

A plug in hybrid is not for everyone. Just like a moped or city bus is not for everyone. We all don't drive around in the same type of car. There are a dozen choices people make when buying a car.
What people don't have is a choice to use their own electricity to drive a production car that has a gasoline engine as backup for long journeys. Some people would like to have a PHEV. There are issues about charging access, there are issues about renewable power, there are issues about oil. We are already hearing that elctric cars have lower mechanical maintenance costs... an interesting topic to follow. If someone drives 10km to work in electric mode and charges up at work, the PHEV set up may be a reasonable choice.

I hate the term “Zero emissions vehicle” which is such a misnomer. Coal provides 50% of the electric power in the US which is used to charge these vehicles, and the generating process is on average only 34% efficient. There are power line transmission losses of 7%, the power supply to the battery charger is about 90% efficient, the battery charging process (not including the charger) is about 90% efficient, and the re-transmission of torque to the wheels via electricity through the electronics and motors is how much? Simple math sows that using coal to charge these zero emissions vehicle is less than 24% efficient whereas an efficient all diesel vehicle can exceed 50%. The true kumbaya tree-hugger who is not a political lackey should be embracing small diesel vehicles. The truly ignorant claim to want to use solar panels to charge these vehicles but the numbers there are even worse, don’t get me started on those efficiencies…

I do not see any mention of the carbon foot print that is additional to the normal car's manufacturing vs. hybrids and EVs. I want to know, what is the total difference for the life of the vehicle? If it takes twice the energy to make an EV then it is very unlikely that, that will be made up for in even a 200,000 life. If there is no additional energy input into the manufacturing of these vehicles then the comparisons are OK. Since the great majority of all electrical production in the US is fossil fuel based: Coal, Oils, Natural gas, I do not buy that you can assume that your energy comes from renewables. Furthermore as far as I know all renewables except for hydroelectric, cost more than they produce. What happens is that the costs are shifted from the owner to the US public. So buy EV you will be subsidized by me involuntarily when you buy it and again when you use it. This is a rip off for the rest of us. Why is this never in print?

St Johsberry owner had an EV back in 1970 that was manufactured in the 18 th century. This is not new. They stopped making them because they were not cos effective. The same goes for Hybrids there vere thousand manufactured during the first word war but went out of production because of the extra cos as soon as gasoline was again available with ot retion tickets. It is only the high price of gasoline that allows todays hybrids to survive.

I have yet to see any data confermint that comercially available solar panels are cost effective. BP has a plant nearby that has abandoned its solar panel at their silicone production site because maintenance was more expensive than the value of electricity provided.

There are those of us whose commute is far more than 13 miles. My commute in my car is about 27 miles round trip to a park & ride parking lot (no place to recharge) and then riding in a van with up to 13 other people the rest of my 185 mile round trip commute. By the way, my gasoline-only car averages 35 to 40 mpg. If there was a better range and lower battery replacement cost for the hybrid cars, it might be worthwhile. As it stands, I don't see it as a viable solution for me. Regarding the length of my commute, I want to work and that distance is where I found a job.

Before BEV really can be efficiently and quickly charged, a PHEV seems to be the most reasonable choice for greener life. We need to pay the cost for greener life. So, green life is not for poor people.

Sure, it's okay to start small, but my original premise was an EV that can replace internal combustion engine cars with no apologies. Rather than EVs that give people the excuse to say "it's not an option for me," as people love to do. I'm not sure what you are referring to when you say "range extender." My goal would be, and EV that can do without the battery, or just have a small battery to provide regenerative braking.
And it isn't just apartment dwellers that are at a disadvantage with battery-powered EVs (and plug-in hybrids). There are many people who own houses with no garage. Check out a lot of older cities up and own the East Coast. There are many people who own houses with garage, but the garage is full of junk (e.g. many or most of my neighbors). We happen to own only one car. I use public transportation to get to work, so even for me, it would be less than ideal to have to rely on one car whose range is limited. So all I'm saying is, I'll get excited when EVs are for the masses by design, rather than being only a second car. And there is work toward that end, has been for some time, but it doesn't get much press. And even when it gets some press, it seems like the press "doesn't get it."

Bert,
None of the numbers I state are assumptions, or based on assumptions. Check out my extensive data gathering on this subject on my website www.evdrive.com. Full details/specs in slide show format.
I have logged 9000 miles of driving without compromise other than range. When I need to go out of town, I take my Honda Civic. My gas consumption has dropped to about 10% (of my 10,000 miles/year) and I have not had to compromise on anything. In fact, the drive quality has improved over the original gas engine in terms of its performance.
We are currently working on a Range extender that will allow driving continiously on fuel of choice. It is small and light enough to not displace cells to maintain a 100 mile pure electric range. Then you have the best of both worlds, until better cells arrive on the market.
Regarding appartment dwellers lack of plug access for charging, is that a reason to not do anything and not begin the gradual transition by those that can?
Once you see the engineering data, then make your judgements. There are some amazing specs on components now and this is just the beginning.

Just to be sure my points aren't misinterpreted, I like the idea of EVs, but don't like or believe much of the hype around battery-powered EVs.
This is instead what seems to be a more credible approach:
http://www.greencarcongress.com/2009/10/dod-ehs-20091005.html
This approach would create EVs that truly can replace internal combustion engine cars. I'd put more resources into this research.